1. Field of the Invention
The present invention relates to an electrical connector, and particularly to a Zero Insertion Force (ZIF) socket connector for interconnecting an electronic package, for example a Central Processing Unit (CPU), with a printed circuit board, for example a mother board.
2. Description of the Related Art
Referring to FIGS. 9-10, two drawing figures substantially adopted from U.S. Pat. No. 4,498,725, an electrical contact 14 to be used in a ZIF socket connector is disclosed. The electrical contact 14 includes two parallel, vertical arms 106 and 108. Channel-shaped strap 110 joins the two arms adjacent their lower ends 112 and spaces them apart. The width of the arms 106 and 108 decrease uniformly upwardly towards their upper ends 116. A pair of fingers 118 project laterally from their attachment to upper ends 116 of the arms 106 and 108. First sections 120 of the fingers 118 converge toward each other. Free ends 122, attached to and extending outward from the converging sections 120, are parallel to each other and are spaced apart by a distance less than the minimum diameter of pins (or leads, see FIG. 11) 117 on an electronic package (not shown) to reliably and electrically connect with the pins 117 when engaged. A lead 124 extends downwardly from the arm 106.
The contacts 14 are stamped out of coplanar stock in a continuous strip. Referring to FIG. 10, a carrier strip 130 is connected to the electrical contact 14 which has not yet been formed into the FIG. 9 structure. A lateral dimension p is defined between outer ends of the fingers 118 of each electrical contact 14, which determines a minimal length of material needed to make an electrical contact 14. Since the arms 106, 108 with the fingers 118 are symmetrically configured with respect to each other, as is known to one of ordinary skill in the pertinent art, for providing dual contacting points to the pins 117 of the electronic package to ensure an electrical connection therebetween, the lateral dimension p is twice of the lateral dimension pxe2x80x2 of each arm 106, 108, which is defined between a center line C of the electrical contact 14 and the outer end of the finger 118, and is comparatively large, thereby consuming a large quantity of material in manufacturing and increasing the cost of the electrical contacts 14, which is obviously not economical to contact manufacturers.
In addition, a pitch pxe2x80x3 is defined between the center lines C of every two adjacent electrical contacts 14 and is comparatively large due to the relatively large lateral dimension p of each electrical contact 14, thereby decreasing the efficiency in both the plating process of the electrical contacts and the assembling process of the electrical contacts to a corresponding insulative housing (not shown).
Furthermore, referring to FIG. 11, as is known to persons skilled in the pertinent art, after the pin 117 is initially inserted between the fingers 118 with zero insertion force, the pin 117 is then pushed to electrically contact with the free ends 122 and the free ends 122 and the converging sections 120 of the arms 106, 108 are slightly pressed outwardly around a beginning portion 109 from which the converging sections 120 begin to converge toward each other. A total length of each finger 118 is relatively small, so an arm of force, which is defined between the beginning portion 109 and the outer end of the finger 118, is also small, thereby resulting in an undesirably large push force for the pin into between the free ends 122.
Furthermore, when the pin 117 is pushed, in the direction as indicated by the arrow B, from between the converging sections 120 to between the free ends 122, acute angles formed between the converging sections 120 and the free ends 122 is encountered since a distance between the converging sections 120 is larger than a distance between the free ends 122, thereby further increasing the push force.
Therefore, an improved electrical contact for a ZIF socket connector is desired.
An object of the present invention is to provide a cost effective electrical contact for a ZIF socket connector which provides also a reliable electrical connection between an electronic package and a printed circuit board.
Another object of the present invention is to provide an electrical for a ZIF socket connector which increases efficiency of the plating and the assembling processes thereof.
Another object of the present invention is to provide an electrical contact for a ZIF socket connector which reduces a push force needed for a pin of an electronic package to electrically contact therewith.
A ZIF socket connector comprises a base, a cover, an actuator and a plurality of electrical contacts in accordance with the present invention. The cover is assembled to the base and is actuated by the actuator to be movable with respect to the base. The electrical contacts are received in the base. Each electrical contact comprises a base portion, a solder portion extending from the base portion, and a contacting portion comprising a pair of arms. Each arm comprises a vertical section extending from the base portion, a horizontal section and a resilient section having free end. The free ends of the resilient sections of the arms are so formed as to have contacting surfaces thereof press therebetween and electrically contact a pin electronic package received on the cover.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.